Steven Pinker on Common Knowledge and Human Behavior

Defining Common Knowledge

• 💡 Common knowledge is a technical concept where "I know that you know that I know that you know it add infinitum," distinct from everyday common sense.
• 🎯 It is essential for coordination in daily life, enabling people to align on arbitrary choices like driving sides or currency value.
• 🧠 Recursive mentalizing refers to "reading the mind of a mind reader," or thinking about thinking, which humans do explicitly and some animals implicitly.

Generating and Impacting Shared Understanding

• ⚡ Conspicuous events or "elephants in the room" instantly generate common knowledge, as everyone sees it and knows others see it.
• 👀 Eye contact is a potent common knowledge generator across species, making private information shared and influencing social dynamics.
• 👑 The story of the "Emperor's New Clothes" illustrates how a public declaration transforms private suspicions into common knowledge, altering social relationships.
• 🇺🇸 Joe Biden's debate performance made his suspected cognitive impairment common knowledge, significantly changing public perception and his political standing.

Common Knowledge in Social Dynamics

• ⚖️ Maimonides' Ladder of Charity ranks charitable acts based on the knowledge states between donor and recipient, with common knowledge being the lowest form due to potential for ulterior motives.
• 👏 The Rashba's "Mitzvah L'farsem" argues that publicizing charity encourages more giving, ultimately benefiting more people.
• 🗣️ Indirect speech, innuendo, and euphemisms are used to convey messages without generating common knowledge, thus safeguarding delicate social relationships (e.g., bribes, sexual overtures, veiled threats).

Norms, Politics, and Societal Shifts

• 📉 Donald Trump's actions demonstrated how flouting norms without public sanction can cause them to fray, as norms are upheld by common expectation.
• 🚫 Cancel culture stems from treating ideas as reflections of character and the urge to publicly punish those who flout moral norms, especially in public arenas like social media.
• 🌍 The fractionation of common knowledge through diverse media platforms contributes to societal polarization and the rise of "alternative facts."
• 🕊️ The territorial integrity norm, which prevents countries from invading each other or disputing borders, is a crucial common knowledge norm for global peace.

Personal and Broader Implications

• 💬 Personally, understanding common knowledge helps in navigating social interactions by being sensitive to the tension between conveying a message and preserving relationships.
• 😳 Blushing serves as a common knowledge generator, signaling an acknowledgment of having flouted a norm and shared understanding of social rules.
• 📊 Resolving societal differences may involve bringing disparate groups together to solve common problems and relying on objective data from trusted, politically neutral sources.